Aurora: Nature's Light Show

The Northern Lights Explained

The aurora borealis or northern lights is one of nature's most dazzling events. Shimmering curtains of color waft in the night air.
Huge arcs and pillars of color dance and float through the dark.

What Causes the Northern Lights?

Although it appears at night, the light show that we call an aurora is actually caused by the Sun.

The Sun is very stormy, constantly sending out solar flares and high-energy charged particles that travel at speeds of up to a million miles per hour.

"Solar wind" is made up of streams of these particles. As a strong solar wind gust enters the Earth's magnetic field and collides with gases in the upper atmosphere, the gases begin to glow in a variety of colors; you'll see shades of green, red, yellow, purple, and blue. The colors depend on the energy level of each gas particle.

When the solar winds ripple through the magnetic field, the curtains of light appear to dance, brighten, or fade.

Because of the nature of Earth's magnetic field, auroras are most often seen in the high latitudes, near the poles.

In the Northern Hemisphere, the event is called the aurora borealis, which means "northern dawn," or northern lights.

In the Southern Hemisphere, it is called the aurora australis, which means "southern dawn," or southern lights.

One of the most colorful auroras in recent history occurred in March 1989. It was visible in Canada and the United States and as far south as Mexico. The electrical surge that accompanied it was so strong that parts of Canada were blacked out all night!

Aurora Viewing Tips

Nobody knows exactly why, but the best time to view auroras is during the months around the spring and autumnal equinoxes, late at night or in the early morning, from about 10:00 P.M. to about 3:00 A.M.

The auroras occur at high latitudes so you generally want to look north on a clear, moonless night from a dark place away from city lights.

If you ever get a chance to see nature's light show, don't miss this spectacular opportunity!

Did you know?

No two light shows are ever the same.

The most common colors are pink and green!

A single active display can produce one trillion watts of electricity.

Some people claim they have heard the northern lights hiss and crackle.

In the coming years, we expect higher levels of solar activity, sunspots, and solar winds. This is good news for fans of the aurora borealis.

Northern Lights Tour!

Join the Almanac for the Northern Lights and Alaska Tour in March, 2015! It's a once-in-a-lifetime experience.